Rear window defogger
Defrosting phase:
After switching on the ignition , the rear window defogger is switched on when operated for the first time for 10 minutes or 17 minutes depending on the coding . Undervoltage monitoring is not active during this period of time.
Post-heating phase:
The post-heating phase starts up if the rear window defogger is activated once again after initial switch-on. Clocked operation of the post-heating phase switches the voltage supply for the rear window defogger relay at alternating intervals of 40 seconds ON and 80 seconds OFF.
Undervoltage monitoring:
Untervoltage cut-out is activeduring the post-heating phase . The terminal 30 voltage is evaluated in the control unit and the relay for the rear window defogger is switched off if the voltage drops below11.4 V . The time counter is stopped . The function indicator , however, does not go out. The relay for the rear window defogger is switched on again if the terminal 30 voltage reaches a value above 12.2 V . For this purpose, the threshold value must be applied for at least 1 second.